Gas engine



I. E. SMITH.

AGAS ENGINE.

APPLICATION FILED JUNE 8, 1918.

1,418,209. Patented May 3o,- 1922.

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GAS ENGINE. APPLICATION FILED JUNE 8'. I9I8.

Patented May 30, 1922'.

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I. E. SMITH.

GAS ENGINE.

I APPLICATION FILED JUNE 8. I9IB. 1,418,209, v Patented May 30, 1922.

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JOIN E. SMITH, OF NEW YORK, N. Y., AVISSIGNOR 0F ONE-THIRD T0 THOMAS T.GAUNT AND :ONE-THIRD 'ro WILLIAM D.

N. PERINE, BOTH 0F NEW. YORK, N. Y.

GAS ENGINE.

.specification of Letters Patent. vPaix-1,11ted May' 30, 1922.

Application Ailed June 8, 1918. Serial` No. 239,014.

To all whom t may concern.'

Be it known that l, JOHN E. SMITH, a citizen of the United States,residing at New York in the county of NewYork and State of New York,have invented certain new and useful Improvements in Gas Engines, ofwhich the following is a specilication. y

This invention pertains to an improved gas engine and to the method ofoperating the same.

The invention has to do more particularly with engines of that typedesigned more es- ;pecially forv use in airplane work, and has for itsmain objects the simplification of the engine and means whereby theamount of air which is utilized in the explosive charge may be variedaccording to the altitude at which the machine is employed or running.The invention has for its further object the production of an enginewherein a single combined intake and exhaust valve is em- .ployed foreach cylinder, which valve may be readily remoyed for repair orreplacement. A further object of the invention is to provide a simplemeans' for introducing lthe fuel into the cylinder through the singlevalve, the fuel being vaporized by the air which is drawn in during theintake stroke of the piston. A further object of the invention is toprovide valve closing mechanism working in timed relation with thepiston so that at low altitudes a portion of the fuel charge may der inorder that the mixture may`not become too rich which would cause apremature explosion of-the charge due to the heat of compression.

The invention is illustrated in the annexed drawings, wherein,-l k

Fi is a sectional elevation of an engine cylinder and its allied parts;f

Fig. 2 a side elevation of the cam operating and adjusting mechanisms;

Fig. 3 a longitudinal sectional view taken on the line III-III of Fig.2;

Fig. 4 an enlar ed end view of the cam;

Fig. '5 a top p an view thereof together with the operating shaft;

Fig. 6 a perspective-view of the cam;

. Figs. 7 to 10 .'nclusive, diagrammatic views showing the relation ofthe valve and the piston in different operative relations;

and v 'Fig 11 a diagram illustrating the power be driven out of the'cylinsection 25, said enlarged portion or stroke and its rela-tion tothe valve movement both in opening and closing and for the air and fuelintake and the exhaust.

It is to be understood that in practice a plurality of cylinders will beemployed, but inasmuch as 'they areJ alike, in form, only one is shown'.

lIn the drawings, 1 denotes the cylinder surmounting the crank case 2.The piston is indicated by 3 and is connected by a pitman 4 to a crank 5secured upon a crank shaft 6 which extends lengthwise of the variousengine'units. The upper end of the cylinder is provided with a largeopening'which approximates the bore of the cylinder. A shoulder 7 isprovided adjacent the opening upon which is placed a ring-shaped valve 9screwed into the outer end of the cylinder and bearing directly upon theupper face of the ring. Extending upwardly from the valve seat is aspider frame 1() having a hub 11 in which is mounted the valve stem 12carrying at its lower end a valve 13 which is adapted to seat againstthe inner face of the valve seat. wardly from the spider -frame and arocker arm 15 is fulcrumed therein, the inner end -of the arm beingrounded and bearing in a block 16 mounted in the upper slotted end tionof spring 18 which encircles the tap` pet rod 19 connected to theopposite or outer end of the rocker arm 15. Said spring takes against abushing 20 mounted in the crank casing 2, and against a collar 21 fixedon the rod. The cam shaft is denoted by 22 and secured'thereon is a cam23, the cam bein .of the form best seen in Figs. 4, 5 and 6.A aid cam isprovided with a bearing portion 24 which is concentric shaft and is alsoprovided with an enlarged section extending through a greater distanceabout the shaft at the inner end of the cam, as denoted by l26,- than itdoes at the outer or forward l end. This enlarged portion 26 merges intothe forward enlarged portion upon an inclined planel or line denoted by2 7, iny Fig. 6, and as -a consequence of this formation, as the camshaft 22 is shifted longitudinally, lthe tappet rod- 19 will vbe heldupwardly for a greater or less time,

A bracket 14 extends outwith the axis ofthe .seat 8 which is held inplace by a ring nut according as it is upon the extended raised portionof the cam or at the outer section where the raised portion is not soextensive. When operating at a high altitude when a greater volume ofair must, owin to its rarefied condition, be impounded 'into thecylinder, the cam is so shifted that the tap pet rod works. upon asmaller active portion of the cam than it does when the engine isoperating at a lower altitude. ln the former case the valve is closedearlier in the compression stroke and in the latter, later inthecompression stroke of the piston.

A pinion 28, Figs. 2 ,and 3, is secured upon the crank shaft 6 andmeshes with a.' gear 29 secured upon the cam shaft 22, lthe gears beingin the ratio substantially llto 2, so that for each two revolutions ofthe engine shaft the cam shaft will make a single revolution.

The cam shaft is so mounted that it may be shifted longitudinally inorder to bring the one 0r another portion of the cam into operativeposition with reference to the tappet rod and to this end l employ arocker arm or lever 30 fulcrumed at one end,.as at 31, and provided atits' upper end with a draw-bar 32, which has attached to it a handle 33through which the lever 30 may be manipulated. A thrust bearing 34 issecuredto the outer end of the shaft 22 and vswiveled in the arm orlever 30. The pinion 28 being relatively 4wide, the gear 29 is alwaysmaintained in mesh' therewith and motlonis transmitted from the engineshaft to the cam shaft at all times when the engine'V pipe 35 (Fig. 1)provided with a nozzle 36 which discharges in a, downward direction overthe valve and the valve opening. A pump, not shown, will b e employed toforce the fuel from the nozzle, the pump being connected up totheoperative parts 0f the engine and working in timed relation therewith.It has been found in actual use that this method of applying the fuel isall sucient and highly eicacious. The ingoin'g air vaporizes the fueland a proper charge or admixture of vaporized fuel and air is obtained.

With the parts in the position shown in lig. l, it will be seen that thevalve is closed and it may be assumed'that a charge has been compressedand is about to be fired. There is about a 10 lead between the firingpoint and the upright top center position of the crank. Upon firing thepiston descends and the power stroke continues through approximately 140to 150, as indicated in the diagram Fig. 11. When the piston reaches thepoint marked No. 2in the dia- Laiaaoe gram, the cam opens the valve andthe engine will exhaust from that point on, pr, in other words, willexhaust through apiroxh mately 220 movement of the shaft. n the upperstroke of the piston, the valve being opened, the cylinder will bescavenged fand,

owing to the position of the cam, the valve will remain open uponthedownward stroke, thus drawing in a fresh charge of air and likewisedrawing in the fuel which is injected over the valve and valve cage.Assuming that the engine is operating at low altitude, the cam will 4beso positioned that the Valve will remain open during a portion of thelnext or compressionstroke, and a portionv of the .fuel will be ejectedin order that the engine may not fire by the heat generatedbycompression. The air at the lower altitude being relatively dense ascompared to that of high altitude, the cam holds the valve open untilthe parts reach the position shown in Fig. 9, when, as will be seen, themovement of the cam .(in the direction of the arrow) will permit thevalve to close and during the balance of the movement ofthe piston thecharge is compressed;

In other words, having reference tol Fig. 11, the air and `fuel intakecontinues from the point marked No. 3 to the point marked No. 5, wherethe valve closes. 1 The charge is then again fired and the cycle aboverecited is repeated. As the machine passes into-higher altitudes, theoperator shifts'the cam so as to bring the tappet rod to that positionalong the inclined face 26 of the cam so that the valve will closeearlier during the compression stroke, this for the reason that the airis rarefied and a greater vvolume to produce the proper exploslve chargebecomes essential. This position is indicated in Fig. 10 wherein theJvalve is' shown as closed while the piston is substantially at thelowest point in its stroke.' The valve at such time closes at the pointmarked No. 4, in Fig. 11, so that the air'and fuel intake passes throughsubstantially 200O and the compression stroke thus extends through 150.There is thus obtained a variation of 7 0 between the time of closing ofthe valve at the low altitude and the time of closing of the valve atthe high altitude, and such arrangement enables the operator to controlthe motor without diiiculty and in accordance with the conditions whichobtain at di'erent altitudes.

An index may be employed in conjunction with the valve positioningmechanism so that the operator may bring the same into the properposition indicated by his altitude instruments.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is,-

1. In a gas engine, 'the combination of a cylinder; a piston workingtherein; a single combined inlet and exhaust valve opening into the clinder and alone controlling the intake an exhaust of the engine; avariable throw cam working in timed relation with the piston and servingto close the valve at different points of the compression stroke; meansunder the control of the operator for adjusting said cam; and means forinjecting fuel directly into the cylinder through the Valve opening whenthe piston is moving throulgh the intake stroke.

2. n a gas engine, the combination of a cylinder; a pistotn workingtherein; a single combined inlet andl exhaust valve, of large area,opening directly into the cylinder and alone controlling the intake andexhaust of the engine; means for injecting fuel through the valveopening directly. into the cylinder during the intake stroke of thepiston; and a variable throw cam controlling the movement of the valve,said cam being soarranged that it may be adjusted to hold the Valve openduring the early part of the compression stroke of the piston, therebypermitting a portion of the fuel charge to be forced out of thecylinder.

3. In a gas engine, the combination of a cylinder; a piston workingtherein; a single combined inlet and exhaust valve opening into thecylinder and alone controlling the intake and exhaust of the engine; afuel nozzle for delivering fuel onto the valve structure while the valveis open; and a4 cam mechanism for operating the valve, the cam beingshiftableto close the valve at different points in the compressionstroke whereby' the explosive charge may be maintained substantiallyconstant irrespective of the density of the surrounding atmosphere.

4. In al gas engine, the combinationv of a cylinder; a piston workingtherein; a single combined intake and exhaust valve locatedk in the headof the cylinder alone controlling the intake and exhaust of the engine;a fuel supply nozzle located adjacent said valve and adapted to ejectfuel thereon during the intake stroke of the piston, the fuel beingvaporized by and admixed with the ingoing air; an adjustable variablethrow cam controlling the closing ofl the valve during the compressionlstroke of the piston; and means under the control of the operator foradjusting the cam.

5. In a gas engine,

cylinder; a piston Working the combination of a thereln; a combinedintake and exhaust valve located in' the head of the cylinder and alonecontrolling the intake and exhaust of the engine; a fuel supply nozzlelocated adjacent said valve and adapted to eject fuel thereon during theintake stroke of the piston, the fuel being vaporized by and admixedwith the ingoing air; and an adjustable cam having a varying degree ofpitch for controlling the closing of the valve whereby the valve may bekept open a longer or shorter period durin the compression stroke of thepiston.

6. hat method of operating gas engines having a combined single exhaustand intake valve, and adapted for use at different altitudes, whichconsists in ejecting fuel upon the valve structure; drawing air inthrough such valve during the intake stroke of the piston of the engineand thereby vaporizing the ,fuel and admixing it with the air to form acombustible charge, and thereafter during the compression stroke varyingthe time of closing of the valve according to the density of thesurrounding atmosphere whereby the effectiveness of the charge w1ll bemaintained substantially constant.

In testimony whereof I have signed my name to this specification.

JOHN E. SMITH.

